Dalian Bay (Chinese: 大连湾; pinyin: dàliánwān), is a bay on the southeast side of the Liaodong Peninsula (Chinese: 辽东半岛) of Northeast China, open to the Yellow Sea (Chinese: 黄海) in the east. Downtown Dalian lies along the southern shore of the bay. Its significance is that it is ice-free year-round, while Jinzhou Bay (Chinese: 金州湾) on the other, northwest side of the peninsula is part of the Bohai Sea (Chinese: 渤海), and is shallow and closed for four months of the winter.
In 1879, about 20 small islands with their bays around Dalian were named Dalian Bay and barbettes for military use were built in Dalian Bay after that. By the end of the Sino-Japanese War of 1894-1895, most of the barbettes were discarded and fishery industry started quickly. Now. only six barbettes are remained and they are located on Monk Island. They were built in between 1887 and 1893. The bay was the rendezvous point for the British fleet for the 1860 assault on China during the Second Opium War.
Dalian Bay has one of the biggest fishing port in Asia and it plays an essential role in Chinese fishery industry. It has become a famous seafood distributing center in 1930s. Thousands of fishers came here for different types of transaction.